Extended depth of field using a multi-focal length lens with a controlled range of spherical aberration and a centrally obscured aperture
US7336430B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 2005 |
| Grant date | Feb 26, 2008 |
| Priority date | — |
| Expiry date | May 5, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/958
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An extended depth of field is achieved by a computational imaging system that combines a multifocal imaging subsystem for producing a purposefully blurred intermediate image with a digital processing subsystem for producing a recovered image having an extended depth of field. The multifocal imaging system preferably exhibits spherical aberration as the dominant feature of the purposeful blur. A central obscuration of the multifocal imaging subsystem renders point-spread functions of object points more uniform over a range of object distances. An iterative digital deconvolution algorithm for converting the intermediate image into the recovered image contains a metric parameter that speeds convergence, avoids stagnations, and enhances image quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.